The agency “issued a lifetime drinking water health advisory of 70 parts per trillion for human exposure to the manmade chemical,” per Albany’sTimes Union.

Neither PFOA nor PFOS is made or used in the U.S. for manufacturing anymore, but the chemicals persist in the environment because of the strength of the carbon-fluorine bond.

According to AccuWeather.com, a study that was published by Environmental Science and Technology Letters found that the combination of toxic chemicals in aqueous film-forming foam (AFFF) has seeped into public water supplies from California to Rhode Island.

According to the report, “the study suggests at least six million people across the U.S. in 2016 had drinking water that exceeded the Environmental Protection Agency's lifetime health advisory for certain acids associated with the foams.”

Researchers from UC Berkeley and Harvard University report that these “highly fluorinated chemicals are linked to cancer, obesity, high cholesterol and endocrine problems, among other concerns,” per AccuWeather.